The logic of campaign spending in mixed-member electoral systems

In this research note we reason that campaign strategies that are strategic in “pure” majoritarian systems and “pure” proportional systems may (or may not) change when the two are combined in a mixed-member electoral system with a majoritarian and a proportional tier. We argue that campaign effort by individual candidates should be a function of the tier or tiers in which the candidate is competing and whether he or she expects to be a strong contender. We then test our theorizing with candidate campaign spending data from New Zealand, which has used a mixed-member system since 1996. We find support for our reasoning regarding when the strategies appropriate for pure majoritarian and pure proportional systems should be adapted when applied in their mixed counterparts.